<!DOCTYPE html>
<html>
<head>
  <title>Bootstrap 实例</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.1.0/css/bootstrap.min.css">
  <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
  <script src="https://cdn.staticfile.org/popper.js/1.12.5/umd/popper.min.js"></script>
  <script src="https://cdn.staticfile.org/twitter-bootstrap/4.1.0/js/bootstrap.min.js"></script>
 <script src="js/d4.js"></script>
</head>
<body>

<div class="container">
  <h2>堆叠表单</h2>
  <form>
    <div class="form-group">
      <label for="email">邮箱:</label>
      <input type="email" class="form-control" id="email" placeholder="Enter email">
    </div>
    
    <div class="form-group">
      <label for="email">姓名:</label>
      <input type="email" class="form-control" id="uname" placeholder="姓名">
      <p>姓名不能重复</p>
    </div>
    
    
    <div class="form-group">
      <label >地址:</label>
      <input type="text" class="form-control" id="address" placeholder="地址:">
      <p style="color:red;display: none" id="addressp" >地址长度不能超过30个字</p>
    </div>
    
    
    <div class="form-group">
      <label >班级:</label>
      <select class="form-control" id="cname">
      	<option value="10">Java10班</option>
      	<option value="11">Java11班</option>
      	<option value="12">Java12班</option>
      </select>
    </div>
    <div class="form-group">
      <label for="pwd">密码:</label>
      <input type="password" class="form-control" id="pwd" placeholder="密码">
    </div>
    <div class="form-group">
      <label for="pwd">再次输入密码:</label>
      <input type="password" class="form-control" id="pwd2" placeholder="密码">
    </div>
    <div class="form-check">
      <label class="form-check-label">
        <input class="form-check-input" type="checkbox"> Remember me
      </label>
    </div>
    <button type="submit" class="btn btn-primary">Submit</button>
  </form>
</div>

</body>
</html>